Automobile radiator hose on diy wood boiler?

Automobile radiator hose is rated for higher pressures and tempatures than PEX.
The price seems close enough,  and I'm interested in a high temperature low pressure system where water travels as steam.
Large diameter copper pipe would be ideal for building what amounts to a water distillery, but the cost of both pipe and fitting would be unthinkable for me.

I looked around tractor by net and other such places,  but could only find people using heater core,  not the hose per say.
Travis,  I'm thinking you probably will have some insight,  given your knowledge of woodburning, boilers, and IC engines, among many other things.

I have wondered the same thing???

In my case I need a wood furnance, but already have a wood boiler, and thought about just placing a raditor inside a plenum and connecting that to my boiler via radiator hose.

The only real difference is pressure. A car or truck has a 7 PSI radiator cap, while a boiler typically has a 12 PSI relief valve, which at nearly twice as much, is pretty significant. The temperature would be the same, as long as the boiler (a misnomer since they do not actually "boil" water, does not actually flash the water to steam) was not actually producing steam. When you produce steam, all bets are off

The pressure cap for the later 7.3s and the 6.0 Powerstroke was 13 or 16 PSI depending on model. The 5.9 Cummins in that time range was 15-16 PSI.

My guess is the hose will be rated high enough to not be bothered by 12psi.

This is a guess, though, and I don't know shit about steam.

What leads you to this over a liquid system?

You already answered your question - higher rating than pex.

Methinks he seeks hydronics - perchance a shower too...

Seen guys do it with soft-copper around the exhaust pipe. Shoo - some black ABS mounted to the foh-by-foh fer a camp shower....

Seriously though, you're probably fine with anything shy of a bendy straw (though I'd pay a nickle to see that!)

But, yes, obviously, pressure is a thing. If the core dumps into a hot-reservoir that is vented to atmosphere, there's no issue. If you're on some closed loop, get the right relief valve and you're fine (Unless it limes over, then you're the Rocket Man).

I'd be more concerned with the metal skeleton that those radiator lines use though. If it isn't copper, stainless, or good plastic, I'm leery of long-term.

I am leaning towards low pressure steam because steam can carry more heat than hot water.
I'm aiming to move the maximum amount of heat during the shortest time period,to match the burn time of a batch box rocket stove.

William Bronson wrote: I am leaning towards low pressure steam because steam can carry more heat than hot water.
I'm aiming to move the maximum amount of heat during the shortest time period,to match the burn time of a batch box rocket stove.

One thing that I failed to mention - even in a low pressure steam system, like the kettle on your stove, condensation creates serious over-pressure conditions.

The condensation of the steam turns into a piston in the pipe, and travels with the force of a freight-train. They call it "Steam-Hammer" but it's the same thing as "Water-Hammer" - actually, it's exactly the same.

Depending on the flow of the steam through the pipe, and the temperature of the pipes themselves, condensation (water - obviously) WILL collect at the bottom of the pipe. Most of the time this is no problem at all, and you just be sure to drain it out, or make the whole line down-hill so that it naturally flows back into your reservoir.

BUT!

IF the water in the pipe gets too high, AND the steam going passed it is too fast, it creates waves (just like wind-driven waves on a lake). IF that wave gets high enough to restrict the flow of the steam over it - it squeezes the steam between it and the top of the pipe. This creates a mini-venturi that then sucks the top of the wave into the top of the pipe. Low pressure leads to extremely high pressure in an instant.

THAT is SUPER SUPER SUPER BAD!!!

That wave that has blocked the flow of steam over it is now a Steam-Driven Piston. BOOM-FLASH-BURN!!!

In that case, it doesn't matter what pipe you use - your skin will melt off. Dead serious.

Now that I've got you terrified (or helped with a renewed respect for the incompressibility of water)...

1. Use larger diameter pipe than you think is necessary.
2. Insulate the crap out of the steam lines.
3. Try to keep the whole system down-hill if you can - so condensation drains nicely into the reservoir.
4. ALWAYS ALWAYS ALWAYS DRAIN THE LINES BEFORE STARTUP!!! Keep your drain open until ONLY steam is coming out.
5. If you can, find a steam-trap.
6. Keep the steam flow velocity low - velocity is different from pressure obviously (though inversely related) - but weird things happen in pipes - like low pressure and high velocity quickly changing into a mini-bomb.

These things are super scary - but DON'T LET IT STOP YOU! Just be aware of it, plan for it, and all is good.

Delta-P is a very, very harsh mistress - but you give her what she wants, she'll keep you toasty :)

If you keep the steam lines as short as possible, super insulated, and drain all the condensation before start-up, you should not have a problem.

As with all things, Caveat Emptor - these are SUGGESTIONS - But, if it makes you feel any safer, I was a Naval Engineer in another life (Sailor Suit and all...) and we knew a lot about steam....

I figure you got this, but I scratched together a diagram to show how you can keep your condensation running downhill.

Would love to see your build when it's done!

Here's the pic:

Spencer,  thank you!
So much good information, lots to chew on.

I was considering using  an insulated   column(?) rising strait from the boiler to a reservoir on an upper floor.
Even oversized,insulated, and safety valve I will pass on what would probably be inevitable failure.

I mostly wanted to use the radiator hose due to the temperature range.
I want no issues with heat damaging piping.

The working PSI listed is also good, but again,  I am aiming to keep  the system open.
I'm talking lid on on a pot open,  plus pressure relief valves in the liquid return lines.
I read a nice explanation of a stream trap,  thank you for cluing me in their existence.

Thinking hard about maxing out the size of the steam carrying pipes at a doable price,  I've come up with another questionable idea.

Aluminum down spout.
Aside from the joints it seems perfect.
Actually,  regular silicon might do for that.
Large,  rust resistant, cheap, down spouts might be be a good choice.
I would have to insulate it myself, and joining it to the top of a boiler vessel would be tricky,  but I can see it working.
I want to direct the steam into a smallish condenser, that would drain into a large reservoir tank.
If I could run the downspout on a slope through my return air duct, I could condense the steam and preheat the
air in one go.
Rather than punching a 4" hole through a foot if brick wall,  maybe I  could  bring a smaller diameter length of radiator hose  to the start of the condensing downspout.
Now I understand something about how the steam path should go to avoid trouble, I think all down hill to a basement reservoir might work.

Please feel free to poke holes in these ideas,  I would rather be wrong than dead!

Spencer,  thank you!
So much good information, lots to chew on.

I was considering using  an insulated   column(?) rising strait from the boiler to a reservoir on an upper floor.
Even oversized,insulated, and safety valve I will pass on what would probably be inevitable failure.

I mostly wanted to use the radiator hose due to the temperature range.
I want no issues with heat damaging piping.

The working PSI listed is also good, but again,  I am aiming to keep  the system open.
I'm talking lid on on a pot open,  plus pressure relief valves in the liquid return lines.
I read a nice explanation of a stream trap,  thank you for cluing me in their existence.

Thinking hard about maxing out the size of the steam carrying pipes at a doable price,  I've come up with another questionable idea.

Aluminum down spout.
Aside from the joints it seems perfect.
Actually,  regular silicon might do for that.
Large,  rust resistant, cheap, down spouts might be be a good choice.
I would have to insulate it myself, and joining it to the top of a boiler vessel would be tricky,  but I can see it working.
I want to direct the steam into a smallish condenser, that would drain into a large reservoir tank.
If I could run the downspout on a slope through my return air duct, I could condense the steam and preheat the
air in one go.
Rather than punching a 4" hole through a foot if brick wall,  maybe I  could  bring a smaller diameter length of radiator hose  to the start of the condensing downspout.
Now I understand something about how the steam path should go to avoid trouble, I think all down hill to a basement reservoir might work.

Please feel free to poke holes in these ideas,  I would rather be wrong than dead!

I have a special place in my heart for any dual-function mechanical systems - condense steam and preheat air in the same gizmo? ABSOLUTELY!!

Your aluminum downspout idea is not bad actually! My first thought was that aluminum is a heat conductor - but so is copper and iron - then it occurred to me that you'll give them a blanket anyways :)

Try that bubble-wrap aluminum foil stuff for the first layer of pipe insul - then wrap it with batting and finally a plastic bag. They do have pipe insulation tubes by the foot, but you're dealing with strange diameters in the downspout, so you may need to improvise.

For sealing the seams, I THINK that the high-temp silicone should work - but a nice liquidy epoxy (check for temp and water tolerance) can be poured along seams. There's also a type of aluminum tape with a waterproof adhesive, don't know about the temp tolerances, but that would be super convenient.

The diagram I made is a "monotube" type boiler - it assumes and needs a certain level of pressure on the cold side to keep fresh water flowing in as the steam exits. That is partially why the reservoir is placed as is - it creates the thermosiphon and, provided it goes fast enough for your purposes, that eliminates the need for circulation - especially as the cooling steam flows downward through the other coil (were it an AC I'd call it an evaporator - in this setup it's a hydronic radiator) - that helps pull the steam and subsequently the boiler feed water.

Convection is our friend!

In any given system, it's just about knowing what phenomena or mechanism you're looking to maximize, and what you need to minimize. With the basic principles, you could design and build a nuclear reactor if you were so inclined - not that this would be strictly permaculture mind you, but you could.... if you were so inclined.

Anywho - depending on where your rocket-stove is, it would be efficient were the reservoir on the same level so as to feed with whatever pressure is created by the water column in the tank.

I hope I've been helpful - I tend to collect information without having anyone to give it to.

If this is helpful - please excuse the try, and DON'T FEEL OBLIGATED IN ANY WAY (not my purpose in helping!), might you take a look and maybe spread some love?: Crowdfund Thing Even simple shares and prayers help... day 13 of 60...

In any case, I am happy about your downspout idea... I may incorporate that in some doohickey or another. :D